1. Field of the Invention
The present invention relates to an apparatus having a flexible mounting mechanism for enhancing vibration resistance and impact resistance. More particularly, the present invention relates to an apparatus such as a portable device for recording and reproducing signals and a removable storage unit pack compatible with the device.
2. Description of the Related Art
Recently, devices for recording and/or reproducing digitized data such as digitized audiovisual signals (i.e., digital signals) are used for various applications. The digital signals are easy to process by computers and are not degraded even when duplicated. Thus, audiovisual devices (hereinafter, simply referred to as xe2x80x9cAV devicesxe2x80x9d) for manipulating and editing digitized signals are widely used, particularly for industrial applications (e.g., television broadcasting, films, and the like).
Hard disk drives (hereinafter, simply referred to as xe2x80x9cHDDsxe2x80x9d) are used as storage units for recording digital signals because of their high storage capacity and recording and reproducing speeds. At present, a 3.5 inch HDD having a capacity of 4xc3x97109 bytes is known, and storage capacity of HDDs is expected to increase at an annual rate of 60%.
AV devices which use removable HDDs have been popularized. An HDD records data in a storage medium and reproduce data stored in the storage medium via a magnetic head which follows information tracks several micrometers wide, from several tens of nanometers above the storage medium. Due to the close ranges between the magnetic head and the storage medium required to properly record or reproduce the data, the HDD is susceptible to damage or malfunction due to vibration and impact.
Vibration or impact may cause such problems that data may not be stored in the storage medium or data stored in the storage medium may not be reproduced. Specifically, vibration or impact may cause the magnetic head to damage the storage medium. In such a case, data stored in the damaged portion of the storage medium may not be reproduced. Vibration or impact may also break the magnetic head.
Maintaining the reliability of the HDD is one of the most important design and manufacturing properties for the AV device incorporating the HDD. Flexible mounting mechanisms are preferably used to improve the vibration and impact resistance of the HDD and thus maintain reliability.
Hereinafter, a conventional HDD pack 63 having a flexible mounting mechanism will be described with reference to FIGS. 13 and 14. FIG. 13 is an isometric exploded view showing the conventional HDD pack 63. FIG. 14 is a cross-sectional view showing the same HDD pack 63.
The HDD pack 63 includes a head disk assembly (hereinafter, simply referred to as an xe2x80x9cHDAxe2x80x9d) 50 and a protective housing 52. As shown in FIG. 14, the HDA 50 includes disks 57 (as magnetic storage media); a spindle motor 58 for supporting and rotating the disks 57; magnetic heads 59 for recording data in the storage media and reproducing data stored in the storage media; arms 60 for supporting the magnetic heads 59; an driving section 61 for positioning the magnetic heads 59; and a casing 62 accommodating all the above-mentioned elements. As shown in FIG. 13, receiving members 51 are fixed on the upper, bottom and side surfaces of the casing 62 of the HDA 50. The protective housing 52 includes an upper plate 53, a frame 54 and a bottom plate 55 and is provided for protection of the HDA 50. The supporting members 56 are provided between the receiving members 51 and the protective housing 52, thereby supporting the HDA 50 in the protective housing 52.
An apparatus which utilizes an apparatus having a removable HDD pack is proposed, for example, in the U.S. Pat. No. 5,253,129.
Since the supporting members 56 can reduce damage to the HDD pack 63 caused by an external force, the HDD pack 63 can be removed from the apparatus and carried by itself. However, conventional removable HDD pack 63 is intended to be incorporated in a stable apparatus.
An HDD pack used in apparatuses carried by users, for example portable AV devices, needs to withstand impact which may be caused when the apparatus is hit by an obstacle or vibrated as the apparatus is transported.
Generally, a conventional HDD can withstand an impact acceleration of approximately 300 G when the HDD is not operated. However, when the HDD pack is dropped on a tile floor from a height of 76 cm, the impact acceleration on the HDD pack is about 1500 G or more.
When an HDD pack is operated in a portable AV device while being moved, the maximum acceptable impact acceleration on the HDD may be as much as about 10 G. The HDD pack built in AV device is required to record and reproduce data with a high reliability even under such circumstances.
Carrying an HDD pack separately from an AV device may induce a vibration acceleration of up to approximately 4 G and at a frequencies of up to approximately several hundred hertz on the HDD pack. When an HDD pack is operated in the AV device while being carried, a vibration acceleration of up to approximately 2 G and at frequency of up to several hundred hertz may be applied to the HDD pack.
Thus, the conventional HDD pack is subject to damage and malfunction caused by impact and vibration of the AV device. The problems caused by vibration include, for example, defective recording and/or defective reproduction of data; damage to the storage medium by the magnetic head which results in defective reproduction of data written in the damaged portions of the storage medium; and breakage of the magnetic head. The problem caused by impact includes, for example, defective recording and/or defective reproduction of data; damage to the storage medium given by the magnetic heads which results in defective reproduction of data written in the damaged portions of the storage medium; and breakage of the magnetic head.
In order to use an HDD as a removable storage unit, the HDD needs to have satisfactory impact resistance to avoid defective recording or reproduction of data, elimination of data, or structural damage, even if the apparatus or the HDD is dropped while being carried or when the HDD is inserted into or ejected from the apparatus. Additionally, satisfactory vibration resistance of the HDD is required to similarly avoid defective recording and/or reproduction of data, elimination of data, or structural damage even while being accommodated in a portable AV device for recording or reproduction.
The force against an HDD varies in type, magnitude and frequency, depending on whether the HDD is carried separately or operated in the portable AV device. The flexible mounting mechanism for the HDD must absorb or counteract the force under any conditions. Conventionally, a small flexible mounting mechanism cannot effectively control both impact and vibration. Since the conventional flexible mounting mechanism is required to be quite larger to reduce both impact and vibration, it is not suitable for portable AV devices.
An apparatus having a flexible mounting mechanism according to the present invention includes a storage section, a casing accommodating and holding the storage section, a protective housing accommodating and protecting the casing, a supporting member provided between the casing and the protective housing for supporting the casing, and a maintaining member supporting the protective housing. The supporting member and the maintaining member have different vibration damping characteristics.
In one embodiment of the present invention, a spring constant of the supporting member is larger than a spring constant of the maintaining member.
In another embodiment of the present invention, the maintaining member supports the protective housing such that the protective housing is removable from the apparatus.
In still another embodiment of the present invention, the protective housing is made of a material that satisfies a relationship,
Gh less than Gf 
where Gh is an impact acceleration at which the protective housing breaks and Gf is an impact acceleration at which the storage section is rendered inoperable.
In one embodiment of the present invention, the material forming the protective housing is a resin.
In still another embodiment of the present invention, the storage section includes a storage medium for storing data, a spindle motor for rotating the storage medium, a head for recording data in the storage medium and reproducing data stored in the storage medium, and a driving section capable of positioning the head at an arbitrary position with respect to the storage medium.
In yet still another embodiment of the present invention, a primary resonance frequency obtained by the spring constant of the supporting member and the total mass of the storage section, the casing, the supporting member and the protective housing is lower than a rotational frequency of the spindle motor.
In one embodiment of the present invention, the apparatus is a portable audiovisual device.
In another embodiment of the present invention, the apparatus is a portable computer.
According to another aspect of the present invention, an apparatus having a flexible mounting mechanism, includes a storage section, a casing accommodating and holding the storage section, a protective housing accommodating and protecting the casing, a supporting member provided between the casing and the protective housing for supporting the casing in the protective housing, and a elastic member provided between the casing and the protective housing. A spring constant k1 of the supporting member and a spring constant k2 of the elastic member have a relationship of k1 less than k2.
In one embodiment of the present invention, the elastic member has a first end and a second end. The first end of the elastic member is fixed to the casing. Moreover, a space is provided between the second end of the elastic member and the protective housing under steady-state conditions.
In another embodiment of the present invention, the elastic member has a first end and a second end. The first end of the elastic member is fixed to the protective housing. Moreover, a space is provided between the second end of the elastic member and the casing under a steady-state.
In still another embodiment of the present invention, the apparatus further includes a receiving member provided in the protective housing. The supporting member is deformed when the second end of the elastic member makes contact with the receiving member.
In yet still another embodiment of the present invention, the elastic member is a metal leaf spring.
In another embodiment of the present invention, the supporting member is a gel-like member.
According to another aspect of the present invention, the apparatus having a flexible mounting mechanism includes a storage section, a casing accommodating and holding the storage section, a protective housing accommodating and protecting the casing and a supporting member for supporting the casing in the protective housing. The supporting member includes a first hollow portion, a second hollow portion, a neck portion having a hollow, and a medium. The first hollow portion communicates with the second hollow portion through the neck portion. Furthermore, the medium flows either from the first hollow portion to the second hollow portion through the neck portion, or from the second hollow portion to the first hollow portion through the neck portion to dissipate impact on the casing.
In one embodiment of the present invention, the apparatus further includes a receiving member having a hole for receiving the neck portion of the supporting member. The receiving member is fixed to the casing.
In another embodiment of the present invention, the supporting member has a bellows-shaped end.
In yet still another embodiment of the present invention, the medium is oil.
In still another embodiment of the present invention, the apparatus further includes a first connector and a second connector and a plurality of flexible conductive wires. The first connector is provided in the casing and electrically connected to the storage section, and the second connector is provided in the protective housing and connected to the first connector via the plurality of flexible conductive wires.
In another embodiment of the present invention, the apparatus further includes a first connector and a second connector and a plurality of flexible conductive wires. The first connector is provided in the casing and electrically connected to the storage section, and the second connector is provided in the protective housing and connected to the first connector via the plurality of flexible conductive wires.
Thus, the invention described herein makes possible the advantage of providing an apparatus and a storage unit having a sufficiently small flexible mounting mechanism that vibration resistance and impact resistance of the storage unit is ensured; no defective recording or reproduction of data is caused by vibration and impact; no damage to the storage medium by a magnetic head is caused by vibration and impact; and no breakage of the magnetic head is caused.
This and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.